"""Tests der Broadphase (Sweep-and-Prune)."""

import random

from sandbox.physics import Body, Vector2
from sandbox.physics.broadphase import find_candidate_pairs
from tests.helpers import material


def _random_scene(seed: int, count: int) -> list[Body]:
    rng = random.Random(seed)
    bodies = []
    for _ in range(count):
        position = Vector2(rng.uniform(0, 400), rng.uniform(0, 300))
        if rng.random() < 0.5:
            bodies.append(Body.circle(position, rng.uniform(5, 30), material()))
        else:
            bodies.append(Body.box(position, rng.uniform(5, 30), rng.uniform(5, 30), material()))
    return bodies


def _overlap(a: Body, b: Body) -> bool:
    a_min_x, a_min_y, a_max_x, a_max_y = a.bounds()
    b_min_x, b_min_y, b_max_x, b_max_y = b.bounds()
    return a_min_x <= b_max_x and b_min_x <= a_max_x and a_min_y <= b_max_y and b_min_y <= a_max_y


def test_matches_brute_force_on_random_scenes() -> None:
    for seed in range(5):
        bodies = _random_scene(seed, 60)
        expected = {
            (min(a.id, b.id), max(a.id, b.id))
            for i, a in enumerate(bodies)
            for b in bodies[i + 1 :]
            if _overlap(a, b)
        }
        found = [(a.id, b.id) for a, b in find_candidate_pairs(bodies)]
        assert len(found) == len(set(found)), "kein Paar doppelt"
        assert set(found) == expected


def test_pairs_are_ordered_by_id() -> None:
    bodies = _random_scene(7, 40)
    for a, b in find_candidate_pairs(bodies):
        assert a.id < b.id


def test_pairs_of_sleeping_bodies_are_skipped() -> None:
    a = Body.circle(Vector2(0, 0), 10, material())
    b = Body.circle(Vector2(15, 0), 10, material())
    c = Body.circle(Vector2(30, 0), 10, material())
    a.put_to_sleep()
    b.put_to_sleep()
    pairs = {(x.id, y.id) for x, y in find_candidate_pairs([a, b, c])}
    assert (a.id, b.id) not in pairs  # beide schlafen
    assert (b.id, c.id) in pairs  # schlafend + wach wird geprüft